Evaporative air conditioner

ABSTRACT

An evaporative air conditioner is provided with a continuously extending water-absorbent air filter pad which is enclosed within a housing so that air entering through openings in the housing will surround the filter pad and flow through the pad substantially uniformly throughout the entire area of the pad. A baffle plate is mounted between the openings in the housing and the pad for deflecting air flowing through the openings into the space between the pad and the housing. A water distribution channel is positioned above the pad for supplying water to the pad, the channel having openings above the pad spaced along the length of the pad. The water distribution channel is supplied with water by a plurality of supply channels which communicate with the distribution channel at spaced locations along the length of the channel so that the pressure of the water is substantially uniform throughout the distribution channel. The filter pad is supported by the top wall of an enclosed water tank, and openings are provided through the top wall of the tank below the filter pad to permit excess water to drain into the tank. An air exhaust tube extends between the top and bottom walls of the tank, and an exhaust grille having an upwardly extending plenum tube which is adapted to extend upwardly through the ceiling of the room to be cooled is telescopingly received in the exhaust tube. A fan may be adjustably mounted in the exhaust tube for drawing air through the filter pad and forcing it into the room.

United States Patent 1 Nagele [451 Feb. 18, 1975 1 EVAPORATIVE AIRCONDITIONER [75] Inventor: Immanuel P. Nagele, Valley Center,

Kans.

[73] Assignee: The Coleman Company, Inc.,

Wichita, Kans.

[22] Filed: Sept. 20, 1972 [21] Appl. No.: 290,490

[52] US. Cl 261/29, 62/DIG. 16, 98/2.14,

' 261/106, 26l/DIG. 4 [51] Int. Cl Blf 3/04 [58] Field of Search26l/DIG. 4, 28, 29, 98,

261/106; 62/DIG. 16, 3l43l6; 98/2.1l, 2.14

[57] ABSTRACT An evaporative air conditioner is provided with acontinuously extending water-absorbent air filter pad which is enclosedwithin a housing so that air entering through openings in the housingwill surround the filter pad and flow through thepad substantiallyuniformly throughout the entire area of the pad. A baffle plate ismounted between the openings in the housing and the pad for deflectingair flowing through the openings into the space between the pad and thehousing. A water distribution channel is positioned above the pad forsupplying water to the pad, the channel having openings above the padspaced along the length of the pad. The water distribution channel issupplied with water by a plurality of supply channels which communicatewith the distribution channel 'at References Cited spaced locationsalong the length of the channel so UNITED STATES PATENTS that thepressure of the water is substantially uniform 1,983,979 12/1934- Graham98/2.l4 throughout e distribution Channel The filter p i 2,237,4974/1941 'Munf0rd, 12 1/1316 4 supported by the top wall of an enclosedwater tank, 2,588,612 3/1952 Brookins 261/28 X and openings are providedthrough the top wall of the 1 6/l957 Montgomery et al. 261'/DIG. 4 tankbelow the filter pad to permit excess water to 2,356,166 10/1953 (308mdrain into the tank. An air exhaust tube extends be- 2933354 9/1961Bonzlerm 26l/ 4 tween the top and bottom walls of the tank, and an ex- 012/1966 Fmd ey haust grille having an upwardly extending plenum tube3,372,911 3/1968 Herboldshe1mer.... 62/314 X whi h da tedt t d rd! throuh th 3,524,398 8/1970 Winfrey 261/98 X c 1 a P 0 ex y g e 3,552,0971/1971 Grasseler 26l/D1G. 4 of the room to be cooled leles9opmglyrecewed 3,640,514 -2/1972 Albritton 261/120X in the exhaust tube- A fany be adJuStahly mounted in the exhaust tube for drawing air through thefilter Primary Examiner-Tim R. Miles P and forcmg 1t mm the room- A t 1Exam 'n Richard L. Chiesa i an 1 er ,3 Claims, 7 Drawing Figures i x 290so- 2: g: 4 T 3 r d 3 48/ I2 a 4 21 y 1 z; t 2 2': r; 1: 7 D 20 50 A a o(I r s3 71 72 a2 79 a2 1 EVAPORATIVE AIR CONDITIONER BACKGROUND Thisinvention relates to evaporative air conditioners, and, moreparticularly, to an evaporative air conditioner which is adapted to bemounted on the roof of a vehicle.

Evaporative air conditioners conventionally include an air filter mediumwhich is saturated with water. Outside or ambient air of relatively lowhumidity is directed through the saturated filter medium, and as the aircomes into contact with the wet material of the filter and the watervapor generated by the saturated filter, a heat exchange occurs. Thevelocity of the air passing through the wet filter increases theevaporation process. The objective with most evaporative 'airconditioners is to saturate the relatively dry entering air with watervapor until equilibrium, i.e., full wet bulb depression, isaccomplished. The entering air will then be saturated to its fullmoisture carrying capability. Expressed in temperature, this would bethe wet bulb reading of the outside air. This heat exchange is felt byoccupants of the room into which the saturated air flows as a sensibletemperature drop equal to the difference of the dry bulb and wet bulbreading of the entering air.

an air flow channel around the pad. The front of the housing is providedwith an air intake grille, and a half fle is mounted behind the intakegrille to deflect the incoming air so that air of excessive velocitywill not pass directly-through the pad. The deflected air flows into theair flow channel, and the back pressure created by the housing enclosureforces the air through the filter pad at a substantially uniform ratethroughout the pad.

DESCRIPTION OF THE DRAWING The invention will be explained inconjunction with an illustrative embodiment shown in the accompanyingdrawing. in which FIG. 1 is a perspective view, partially broken away.of an air conditioner formed in accordance with the in vention and shownmounted on the roof'of a room to be cooled;

p In attempting to achieve the foregoing objectives,

substantially uniformly throughout the entire area thereof. As a resultportions of the filter medium may become relatively dry due to thepassage of an excessive amount of air, and air passing through theseportions will not become fully saturated. Once a relatively dry area isestablished, even more air will tend to flow through this because thedry filter material provides less air resistance than wetfiltermaterial. Problems have also arisen in supplying water uniformlythroughout the length of the filter medium and in insuring that the airpasses from the filter medium into the room without leaking back to theoutside.

SUMMARY ported by an enclosed water tank, and an exhaust tube extendsfrom the enclosure through the top and bottom walls of the tank. Air canflow through the exhaust tube only by flowing through the saturatedfilter pad, and air is caused to flow through the pad substantiallyuniformly throughout the length thereof by a housing which encloses thepad and is spaced therefrom to form a central drain opening 23.

FIG. 2 is a longitudinal sectional view of the air conditioner of FIG.1;

FIG. 3 is a fragmentary sectional view taken along the line 3+3 of FIG.2;

FIG. 4 is an exploded view of the air conditioner;

FIG. 5 is a fragmentary sectional view taken along the line 55 ofFIG. 2;

FIG. 6 is a fragmentary bottom plan view of the water distribution tray;and FIG. 7 is a perspective view, partially broken away, of the ceilinggrille'and the exhaust tube.

DESCRIPTION OF SPECIFIC EMBODIMENT Referring first to FIGS. 1 and 2, thenumeral 10 designates generally an evaporative air conditioner whichincludes an outer housing or shroud ll enclosing a generallyrectangularly shaped air filter pad l2 which is supported by an enclosedwater tank 13. Water is supplied to the top of the filter pad by a waterdistribution tray 14 which is supported by the filter pad and whichcovers the enclosure formed by the filter pad. The unit is adapted to bemounted on a roof R of a vehicle such as a travel trailer, motor home,or other-recreational vehicle, and. air. is withdrawn from the enclosureof the filter pad by a fan 15 which is mounted within'an exhaust tube 16which extends through the water, tank,

Referring now to FIGS. 2 and 4, the enclosed water tank 13 is generallyrectangular in outline and includes a bottom wall 18, an upstandingperimetric side wall 19, and a top wall 20 which includes an upstandingedge flange 20a which is secured to the periphery of the side wall. Thetop wall is provided with a generally V-shaped well or channel 21adjacent the outer periphery of the tank, and a plurality of downwardlyextending embossments or dimples 22 are formed in the top wall atthebottom of the .channel, each dimple having The generally rectangularlyshaped filter pad 12 is positioned in the bottomof the V-shaped well 21in the top wall of the tank and extends upwardly to form an airenclosure therewithin. The filter pad can be formed of a variety of wellknown water-absorbent materials through which air can pass, and theparticular filter illustrated is formed of wood excelsior 25 which isenclosed and supported between a pair of wire grids 26 and 27. I

The top of the air enclosure defined by the air filter is closed-by thewater distribution tray 14 which fits over the filter pad and issupported thereby. The distribution tray is formed of top and bottomplastic plates 28 and 29 which are suitably sealed together, as byultrasonic welding, and both of the trays include depending perimetricflanges 28a and 290 which extend below the top edge of the filter pad.As can be seen best in FIGS. 1 and 6, the bottom tray 29 is formed toprovide an outer peripheral downwardly extending channel or groove 30which extends around the entire periphery of the tray above the filterpad and a plurality of downwardly extending channels or grooves 31 whichextend outwardly from a cavity formed by a central cup 32 to thedistribution channel 30. The distribution channel is provided withsubstantially uniformly spaced openings 33, and the supply channels 31communicate with the distribution channel at substantially equallyspaced locations around the length of the distribution channel.

The central cup 32 is provided with a central opening 34 into which aflexible water hose 35 can be inserted. The flexible hose 35 is part ofa conventional water pump assembly 36 which is positioned within thewater tank and which extends through the top wall of the tank. Water W(FIG, 1') is pumped from the reservoir formed by the tank by the pumpinto the central cup 32 of the water distribution tray, and the waterflows outwardly through the plurality of supply channels 31 to theperimetrically extending distribution channel 30. Water-is forcedthrough the openings 33 in the distributionchannel in the form of waterjets J (FIG. 1) which saturate the filter pad. Because water is suppliedto the distribution channel at substantially uniformly spaced locationsaround the length of the channel, the water pressure within thedistribution channel is maintained substantially constant, and there islittle pressure drop between perforations in the channel. Accordingly,the water is supplied to the filter pad substantially uni formly aroundthe entire length of the pad.

Excess water which is not evaporated by air passing through the filteraccumulates in the V-shaped well 21 in the top cover of the tank and.drains through the openings 23 into the water reservoir. This iscontrolled by the number and size of the openings 23 to permit back flowof the water in the well into the filter pad by capillary action ifportions of the pad are not sufficiently saturated. The water reservoiris fully enclosed except .for these openings, and excessive splashoverfrom the tank as the vehicle turns a corner or makes a the front edgeofthe distribution tray and holds the tray against the filter pad. Thebottom of the baffle includes a forwardly extending flange which extendsforwardly above the upper edgeof the water tank where the top and sidewalls are joined and substantiallyprevents the passage of air betweenthe bottom of the baffle and the water tank. The baffle is seen to bespaced forwardly of the filter pad and extends beyond the sides of thefilter pad and terminates in rearwardly extending side portions 51(FIGS. 2 and 4).

The housing 11 includes top and bottom walls 54 and which taper togetherat the rear end of the housing, and side walls 56 and 57.The front endof the housing is provided with an air intake opening 58 which iscovered by a screen or grille 59, and air intake louvers are providedalong the sides of the housing for about half the length thereof. Thebottom wall of the housing is provided with an enlarged opening 61 whichis sized to permit the housing to be moved downwardly over the baffleassembly and the water tank to enclose the baffle, filter pad, and thewater tank. The Z-shaped retainer flange 49 of the baffle assemblyincludes a pairof upwardly extending bolts 62 (FIG. 4), and theretaining channel 46 includes a pair of upwardly extend-' ing bolts 63.These bolts are received by openings in the top of the housing as thehousing is lowered over the water tank, and the housing is secured byacorn nuts 64 which are threaded onto the bolts 62 and 63.

Referring to FIG. 3, the housing is spaced from the filter padaround-the entire periphery of the pad, and

sudden stop is thereby prevented. Water which does flow outwardlythrough the openings will be absorbed by the pad or substantiallyretained in the well of the tank top.

The water tank 13 is supported in a generally rectangular metal basepan38 having a central rectangular opening 39 (FIG. 4). A generallyrectangular sealing gasket 40 can be positioned between the bottom wallof the tank and the base pan around the exhaust tube of the tank and thecentral opening of the base pair. The water distribution tray 14 is heldagainst the top of the filter pad by a pair of front and a pair of rearbrackets 42 and 43 which are secured by bolts 44 (FIG. 2) to theupstanding periphery 45 of the base pan. The upper ends of the rearbrackets'43 are boltably secured to a cross channel 46 which extendsacross the top of the distribution tray from one of the rear brackets tothe other. i

The upper ends of the front brackets 42 are secured to a baffle assembly47 which includes a generally verti- Cally extending baffle or deflectorplate 48 and a generally Z-shaped retainer flange 49 which extends alongperiphery of the filter pad.

A fan motor 65 is supported within the exhaust tube 1 6 by four equallyspaced brackets 66 which are supported above the upper end of theexhaust tube by four brackets 67 which are secured to the exhaust tubeby bolts 68. A drive shaft 69 extends downwardly from the fan motor, andthe fan blade 15 is adjustably secured to the drive shaft so that theposition of the fan blade along the drive shaft can be varied asdesired.

The roof R of the room to be cooled, which may be the interior of a'recreational vehicle or other vehicle, is provided with a rectangularopening 70 therethrough, and the base pan 38 is secured to the roof by arectangular mounting frame 71 (FIGS. 2 and 4) and four bolts 72 whichextend between the mounting frame and the base pan and clamp themounting frame and the base pan to the roof. A rectangular gasket 73 canbe positioned between the roof and the base pan around the opening inthe roof to provide a weathertight seal. The base pan can be secured tothe roof without providing any holes through the roof and withoutremoving the housing 11 from the remainder of the air conditioner.

After the base pan is clamped to the roof, a ceiling shroud assembly 75is secured. The ceiling shroud assembly includes a generally rectangularcover plate 76 having a rectangular central opening and a upwardlyextending cylindrical plenum tube 77. A louver assembly 78 is removablyattached to the cover plate 76 and includes movable louvers 79 which canbe moved .to

fully close the central opening of the cover plate or to vary the amountof air flowing into the room.

The louver assembly is installed by inserting the plenum tube 77 throughthe opening formed in the roof of the vehicle and into the exhaust tube16. The exhaust tube is sized to telescopingly receive the plenum tuberelatively snugly, and the plenum tube is pushed upwardlyin the exhausttube until the cover plate 76 engages the bottom surface of the roof.The exhaust tube is provided with four radially outwardly extendingenlargements 80 (FIGS. 2 and 5) which are spaced about 90 apart, and thefour support brackets 67 which are secured to the upper end of theexhaust tube by the bolts 68 extend downwardly along the inside of thetube in line with these cavities. The cover plate 76 is secured to thelowerends of the support brackets 67 by attaching bolts 82, which holdthe cover plate tightly against the roof. Thereafter, the louverassembly 78 can be secured to the cover plate by screws 83.

The plenum tube 77 provides a fixed plenum chamber downstream of thelouver assembly 78, and the position of the fan blade relative to theplenum tube can be adjusted before the louver assembly is installed toprovide maximum efficiency. The fan blade is adjustably mounted on thedrive shaft 69 of the fan motor,

and after the cover plate 76 is attached to the support brackets 67, thefan blade can be adjusted as desired to accommodate roofs of differentthicknesses. For maximum efficiency it is suggested that the position ofthe fan blade on the drive shaft be adjusted so that about one-third ofthe vertical depth of the fan blades is below the upper edge of theplenum tube. The air drawn by the fan will be forced by the fan into theplenum tube, and maximum air flow will be available for distribution bythe louver assembly. Loss of air through the periphery of the coverplate is substantially prevented.

a certain amount of water is absorbed by the capillary action of thepad.

The air conditioner is designed for use when the vehi- .cle is eithermoving or is stationary. When the vehicle is stationary, air may bedrawn inwardly through the openings in the housing by the fan 15. Whenthe vehicle is moving, air flows through the openings in the housingwhether or not the fan is being operated. The air intake grille 59 facesthe front of the vehicle, i.e., the direction in which the vehiclegenerally moves, and air will flow into the housing through the intakegrille and the side louvers 60. Air which enters through the frontintake grille is deflected by the front baffle 48 to the flow channelbetween the sides of the filter pad and the housing as-illustrated bythe arrows in FIG. 3. Air which enters through the side louvers willalso flow into the flow channel between the filter pad and the housing.Since air will generally enter the housing at a faster rate than it canpass through the water soaked filter pad, particularly when the vehicleis moving, a back pressure will be created within the enclosure of thehousing between the housing and the filter pad. This back pressure willcreate a substantially uniform pressure around the outside of the filterpad, and air will be forced through the-filter pad at a substantiallyuniform rate throughout the entire area thereof as indicated by thearrows in FlG.'3, including the front portion of the filter pad which isspaced rearwardly of the baffle 48.

The mounting plate 71 and the telescoping feature ofthe plenum tube ofthe ceiling shroud assembly permits fast and accurate installation ofthe air conditioner. The air conditioner can be installed withoutdrilling holes through the roof, and the telescoping feature of theplenum tube permits accurate centering of the ceiling assembly.

A pair of water filling tubes 84 and 85 extend into the interior of thewater tank above the normal water level and are equipped with male andfemale fittings 86 and 87, respectively, which may be connected when thehoses are not being used. When the tank is to be filled, one or theother of the filling hoses 84 and 85 is connected to a suitable sourceof water depending upon the type of connection on the water source, andthe other hose can function as an overflow drain tube to preventexcessive filling.

A drain tube 88 is connected to the bottom of the tank above the ceilingcover plate 76 for draining the water reservoir when the air conditionerwill not be used for a period of time. The drain tube can be con- As theair passes through the filter pad, dust and other foreign particles arefiltered from the air, and the air is saturated with water. The cooled,saturated air is been set forth for the purpose of illustration, it willbe understood that many of the details herein given may be variedconsiderably by those skilled in the art without departing from thespirit and scope of the invention. 1

Iclaim: I

1. An evaporative air conditioner adapted to be mounted on a vehiclecomprising a housing having front and rear ends, the housing havingopenings provided in the front end to permit inward flow of air as thevehicle moves forward, a tank within the housing providing a liquidreservoir and having a bottom wall and an upwardly extending side wall,a liquid-absorbent air filter pad supported above the tank and having anupwardly extending closed continuous shape defining a central enclosure,cover means above the filter padv for closing the top of the centralenclosure so that air can enter the central enclosure only through thefilter pad, air exhaust means extending through the bottom housing andthe filter pad and behind the openings in the front end of the housingto prevent direct impingement of air flowing through the openings on thefilter pad and to deflect the air into the air flow space between thehousing and the fllter pad.

2. The air conditioner of claim 1 in which the liquid supplying meanscomprises a fluid supply cavity formed in the cover, a fluiddistribution channel formed in the cover above the fllter pad andextending around the entire periphery of the pad, a plurality of fluidsupply 10 channels formed in the cover extending from the fluid supplycavity to the fluid distribution channel at substantially uniformlyspaced locations along the length of the distribution channel, and meansfor supplying pressurized liquid to the fluid supply cavity.

3. The air conditioner of claim 1 in which the filter pad is generallyrectangular and includes afront portion which extends generallytransversely to the inward flow of air through the front end openings inthe housing and a pair of side portions which extend rearwardly from thefront portion, the baffle extending laterally beyond the side portionsof the filter pad.

1. An evaporative air conditioner adapted to be mounted on a vehiclecomprising a housing having front and rear ends, the housing havingopenings provided in the front end to permit inward flow of air as thevehicle moves forward, a tank within the housing providing a liquidreservoir and having a bottom wall and an upwardly extending side wall,a liquid-absorbent air filter pad supported above the tank and having anupwardly extending closed continuous shape defining a central enclosure,cover means above the filter pad for closing the top of the centralenclosure so that air can enter the central enclosure only through thefilter pad, air exhaust means extending through the bottom wall of thetank for permitting air to flow from the central enclosure of the filterpad, means for supplying liquid to the filter pad, the housing beingspaced laterally outwardly from the filter pad around the entireperiphery of the filter pad to provide a continuous air flow spacebetween the housing and the filter pad around the entire periphery ofthe filter pad, and an imperforate baffle plate positioned between thefront end of the housing and the filter pad and behind the openings inthe front end of the housing to prevent direct impingement of airflowing through the openings on the filter pad and to deflect the airinto the air flow space between the housing and the filter pad.
 2. Theair conditioner of claim 1 in which the liquid supplying means comprisesa fluid supply cavity formed in the cover, a fluid distribution channelformed in the cover above the filter pad and extending around the entireperiphery of the pad, a plurality of fluid supply channels formed in thecover extending from the fluid supply cavity to the fluid distributionchannel at substantially uniformly spaced locations along the length ofthe distribution channel, and means for supplying pressurized liquid tothe fluid supply cavity.
 3. The air conditioner of claim 1 in which thefilter pad is generally rectangular and includes a front portion whichextends generally transversely to the inward flow of air through thefront end openings in the housing and a pair of side portions whichextend rearwardly from the front portion, the baffle Extending laterallybeyond the side portions of the filter pad.